Video: Dragon arrives at space station

SpaceX engineers ran through a customary prelaunch countdown test Saturday and fired the Falcon 9 rocket’s nine Merlin main engines at Cape Canaveral ahead of liftoff Monday with 2.2 tons of supplies and experiments for the International Space Station.

Follow the key events of the Falcon 9 rocket’s ascent to orbit with five more Iridium Next communications satellite and the U.S.-German GRACE-Follow On climate research mission.

NASA has agreed to allow its astronauts to fly on reused Crew Dragon spaceships and Falcon 9 boosters beginning as soon as SpaceX’s third launch of a crew to the International Space Station, a mission expected to launch next year.